This specification covers self-contained automatic shutoff valves (also known as excess flow valves) for air or nitrogen service. They are intended to be installed as safety devices to quickly and automatically shut off flow under certain excess flow conditions caused by a downstream failure or casualty, such as a hose rupture. Automatic shut-off valves shall be of the following types, styles, sizes, pressure ratings, and end connections: Types I and II; Styles 1 and 2. Each automatic shut-off valve must pass the following tests: visual examination; hydrostatic shell test; seal tightness test; external leakage test; and set-point test.

1.1 This specification covers self-contained automatic shut-off valves (also known as excess flow valves) for air or nitrogen service. They are intended to be installed as safety devices to quickly and automatically shut off flow under certain excess flow conditions caused by a downstream failure or casualty, such as a hose rupture.

1.2 The values stated in this specification in inch-pound units are to be regarded as the standard. The SI equivalents shown in parentheses are provided for information only.